The gas industry has long been interested in sulfur recovery technology for applications to gaseous streams resulting from the treatment of “sour” natural or synthetic gas (also referred to as “sour gas” herein) resources to render them commercially useful. Many gas resources contain significant quantities of hydrogen sulfide, carbon dioxide and other contaminants, including, for example, aromatic hydrocarbons, benzene, toluene, mixed xylenes, ethylbenzene, and the like, rendering them unsuitable for commercial use.
Sour gas can cause extensive damage to the gas containing equipment if not properly processed. The combustion of sulfur compounds produces serious air pollutants and eventually produces acid rain when combined with water. These sulfur compounds are poisonous and lethal to humans and animals, and are corrosive to metals and other materials used for the handling and transporting gas.
In order to reduce health and environmental hazards and to meet industry specifications, the hydrogen sulfide and carbon dioxide concentrations in sour gas are ordinarily reduced by regenerative gas-treatment systems. These systems typically contact a sour gas directed into an absorption column with an absorption solution that removes hydrogen sulfide, carbon dioxide and other substances, such as light mercaptans, carbonyl sulfide, from the sour gas. The absorption solution is then regenerated and reused in the system. Recovered hydrogen sulfide is either burned off into the atmosphere or, more commonly, directed to a sulfur recovery plant, such as a Claus plant. Similarly the recovered carbon dioxide can be used as an inert gas or a raw material for food and chemical industries, and agricultural applications. The process of removing hydrogen sulfide, carbon dioxide, and other impurities is referred to as sour gas sweetening.
When sour feed gas is sweetened, the absorbent may exhibit an increase in temperature. Such an increase may occur due to an exothermic reaction, or due to physical characteristics of the process.
Accordingly, it is desirable to provide novel methods and apparatuses for enhancing absorption of acid gas components from sour feed gas. It is also desirable to provide methods and apparatuses for providing interstage cooling of liquid absorbent in columns for absorbing acid gas components. Furthermore, other desirable features and characteristics will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.